Controlling The Concentration Of Color Toner; Outline - Canon 1130 Service Manual

C. Controlling the Concentration of Color Toner

1. Outline

To determine the length of time for color toner supply operation, the concentration of color
toner on the developing cylinder is measured, thereby computing the change in toner density.
Then, the density of the sample image on the photosensitive drum is measured to detect the change
in toner density on the photosensitive drum.
These two items of data are used to determine the amount of toner to be supplied from the
hopper.
Table 6-402 shows the major functions of the color toner concentration mechanism:
Item
Detecting the concentration
Controlling the initial concentration
(reference concentration)
Measuring the concentration of toner
Controlling the toner supply operation
Controlling LED deterioration
Measuring and generating
the image density on the drum
The following shows the flow of operations used to supply color toner:
* 10 copies in CLC1100/1120/1130/1150, 25 copies in CLC1140/1160/1180
COPYRIGHT © 2002 CANON INC.
Light is directed to the developer, and the reflected light
is measured (photo detection).
Measures the concentration of the starter developer at
time of installation or replacement of the developer.
Measures the concentration of the developer on the
developing cylinder during copying operation.
The target concentration and the concentration during
copying operation are compared to determine the
amount of toner to supply.
Light coming directly from the LED is measured by the
photodiode used for the generation of reference signals
to find out the degree of deterioration in the intensity of
the LED.
Measures the density of the sample image on the
photosensitive drum, and determines the target
concentration of toner.
Start key ON
1st copy Measures the concentration of toner on the developing cylinder.
2nd copy Measures the concentration of toner on the developing cylinder.
Measures the concentration of toner on the photosensitive drum for
every 10 copies.*
Computes the change in toner density from two items of data
(concentration on the developing cylinder and on the photo]
sensitive drum) to determine the amount of color toner to supply.
CANON CLC1100/1130/1150/1160/1180 REV.2 FEB. 2002 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 6 IMAGE FORMATION SYSTEM
Description
Table 6-402
6-31